London - Arena O2 - Meet & Greet

Hi guys
I wonder if there will be Meet & Greet in London, how and by whom it is organized, how it is possible to participate / win a chance to meet them.
If there M&G, how would it be possible to get autographs and take pictures with them before or after the show?
Is there any chance to be in the soundcheck?
I am Brazilian, I'm going far away to London to watch the show of the band I love the most, and would love to have the opportunity to see them up close.
I appreciate if someone can help with these issues.
Flávia